I talked to Dimi, Lionel and Alexandre on IRC about this.
This is what they had to say:
Lionel didn't think it should be scrapped however he proposed a system whereby bugs that didn't have any activity for two releases or more would be automatically closed. If you wanted to keep a bug open users would have to post reports of behaviour with current releases.
Dimi thought it should be kept as well, but thought the UI could be improved a lot: for instance a mail based interface would be good. He also thought a dedicated triage guy would be great. Realistically though that's not likely to happen anytime soon. Alexandre basically agreed with this view, I think.
I don't have a strong opinion either which way ... I used to read wine-bugs back when I worked only as a volunteer but usually people come into IRC with apps they'd like to get working and I tended to do that instead. I still do IRC "app on demand" type bugfixing occasionally :)
thanks -mike